Yealink SIP-T2XP Administrator's Manual page 265

jitter, due to message recombination of transmission or receiving equipment (e.g.,
timeout handling, retransmission mechanism, buffer under run).
Noisy equipment, such as a computer or a fan, may cause voice interference. Turn

off any noisy equipment.
Line issues can also cause this problem; disconnect the old line and redial the call

to ensure another line may provide better connection.
A remote phone book is placed on a server, while a local phone book is placed on the
IP phone flash. A remote phone book can be used by everyone that can access the
server, while a local phone book can only be used by a specific phone. A remote phone
book is always used as a central phone book for a company; each employee can load
it to obtain the real-time data from the same server.
Both user name and register name are defined by the server. User name identifies the
account, while register name matched with a password is for authentication purposes.
Display name is the caller ID that will be displayed on the callee's phone LCD screen.
Server configurations may override the local ones.
IP phones support remote reboot by a SIP NOTIFY message with "Event: check-sync"
header. When receiving a NOTIFY message with the parameter "reboot=true", the IP
phone reboots immediately. The NOTIFY message is formed as shown:
NOTIFY sip:<user>@<dsthost> SIP/2.0
To: sip:<user>@<dsthost>
From: sip:sipsak@<srchost>
CSeq: 10 NOTIFY
Call-ID: 1234@<srchost>
Event: check-sync;reboot=true
Troubleshooting
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